成人特发性局灶节段性肾小球硬化病248例临床病理分析

目的 重新评价肾活检标本中特发性局灶节段性肾小球硬化病（FSGS）的发生率、主要临床及病理特点。方法 收集1994年7月～2000年7月间248例特发性FSGS的患者,观察肾组织的光镜、 荧光及电镜的特点,根据肾小球病变将特发性FSGS分为3种亚型。结果 248例成人特发性局灶节段肾小球硬化占同期肾活检的12.4%,占成年人原发性肾小球疾病的19.0%,以18～30岁为发病高峰年龄（约占44.4%）。临床表现为不同程度的蛋白尿,以肾病综合征为表现者143例（占57.7%)。FSGS的3种病理亚型中,经典型FSGS仍占绝大多数（91.5%),尖端型为4.4%,塌陷型为4.1%,肾活检时,约1/3以上为肾功能不全（约占35.1%）。13例尿毒症中76.9%病理亚型为塌陷型。结论 局灶节段性肾小球硬化病约占原发性肾小球病1/5,FSGS患者肾活检时,除表现为蛋白尿、肾病综合征外,肾功能不全也较常见。塌陷型FSGS常表现为进行性的不可逆的肾功能衰竭,其预后差。     

Targeting tissue-resident memory CD8+ T cells in the kidney is a potential therapeutic strategy to ameliorate podocyte injury and glomerulosclerosis

1. Download : Download high-res image (142KB)
2. Download : Download full-size image

     

End-Stage Renal Disease and Mortality Outcomes Across Different Glomerulonephropathies in a Large Diverse US Population

Objective

To compare renal function decline, incident end-stage renal disease (ESRD), and mortality among patients with 5 common glomerular diseases in a large diverse population.

Podocyte loss involves MDM2‐driven mitotic catastrophe

Podocyte apoptosis as a pathway of podocyte loss is often suspected but rarely detected. To study podocyte apoptosis versus inflammatory forms of podocyte death in vivo, we targeted murine double minute (MDM)‐2 for three reasons. First, MDM2 inhibits p53‐dependent apoptosis; second, MDM2 facilitates NF‐κB signalling; and third, podocytes show strong MDM2 expression. We hypothesized that blocking MDM2 during glomerular injury may trigger p53‐mediated podocyte apoptosis, proteinuria, and glomerulosclerosis. Unexpectedly, MDM2 blockade in early adriamycin nephropathy of Balb/c mice had the opposite effect and reduced intra‐renal cytokine and chemokine expression, glomerular macrophage and T‐cell counts, and plasma creatinine and blood urea nitrogen levels. In cultured podocytes exposed to adriamycin, MDM2 blockade did not trigger podocyte death but induced G2/M arrest to prevent aberrant nuclear divisions and detachment of dying aneuploid podocytes, a feature of mitotic catastrophe in vitro and in vivo. Consistent with these observations, 12 of 164 consecutive human renal biopsies revealed features of podocyte mitotic catastrophe but only in glomerular disorders with proteinuria. Furthermore, delayed MDM2 blockade reduced plasma creatinine levels, blood urea nitrogen, tubular atrophy, interstitial leukocyte numbers, and cytokine expression as well as interstitial fibrosis. Together, MDM2‐mediated mitotic catastrophe is a previously unrecognized variant of podocyte loss where MDM2 forces podocytes to complete the cell cycle, which in the absence of cytokinesis leads to podocyte aneuploidy, mitotic catastrophe, and loss by detachment. MDM2 blockade with nutlin‐3a could be a novel therapeutic strategy to prevent renal inflammation, podocyte loss, glomerulosclerosis, proteinuria, and progressive kidney disease. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Rapid Response to Cyclosporin A and Favorable Renal Outcome in Nongenetic Versus Genetic Steroid–Resistant Nephrotic Syndrome

Background and objectives

Treatment of congenital nephrotic syndrome (CNS) and steroid–resistant nephrotic syndrome (SRNS) is demanding, and renal prognosis is poor. Numerous causative gene mutations have been identified in SRNS that affect the renal podocyte. In the era of high–throughput sequencing techniques, patients with nongenetic SRNS frequently escape the scientific interest. We here present the long-term data of the German CNS/SRNS Follow-Up Study, focusing on the response to cyclosporin A (CsA) in patients with nongenetic versus genetic disease.

Design, setting, participants, & measurements

Cross–sectional and longitudinal clinical data were collected from 231 patients with CNS/SRNS treated at eight university pediatric nephrology units with a median observation time of 113 months (interquartile range, 50–178). Genotyping was performed systematically in all patients.

Results

The overall mutation detection rate was high at 57% (97% in CNS and 41% in SRNS); 85% of all mutations were identified by the analysis of three single genes only (NPHS1, NPHS2, and WT1), accounting for 92% of all mutations in patients with CNS and 79% of all mutations in patients with SRNS. Remission of the disease in nongenetic SRNS was observed in 78% of patients after a median treatment period of 2.5 months; 82% of nongenetic patients responded within 6 months of therapy, and 98% of patients with nongenetic SRNS and CsA–induced complete remission (normalbuminemia and no proteinuria) maintained a normal renal function. Genetic SRNS, on the contrary, is associated with a high rate of ESRD in 66% of patients. Only 3% of patients with genetic SRNS experienced a complete remission and 16% of patients with genetic SRNS experienced a partial remission after CsA therapy.

Conclusions

The efficacy of CsA is high in nonhereditary SRNS, with an excellent prognosis of renal function in the large majority of patients. CsA should be given for a minimum period of 6 months in these patients with nongenetic SRNS. In genetic SRNS, response to CsA was low and restricted to exceptional patients.     

Sphingomyelinase-Like Phosphodiesterase 3b Expression Levels Determine Podocyte Injury Phenotypes in Glomerular Disease

Diabetic kidney disease (DKD) is the most common cause of ESRD in the United States. Podocyte injury is an important feature of DKD that is likely to be caused by circulating factors other than glucose. Soluble urokinase plasminogen activator receptor (suPAR) is a circulating factor found to be elevated in the serum of patients with FSGS and causes podocyte αVβ₃ integrin-dependent migration in vitro. Furthermore, αVβ₃ integrin activation occurs in association with decreased podocyte-specific expression of acid sphingomyelinase-like phosphodiesterase 3b (SMPDL3b) in kidney biopsy specimens from patients with FSGS. However, whether suPAR-dependent αVβ₃ integrin activation occurs in diseases other than FSGS and whether there is a direct link between circulating suPAR levels and SMPDL3b expression in podocytes remain to be established. Our data indicate that serum suPAR levels are also elevated in patients with DKD. However, unlike in FSGS, SMPDL3b expression was increased in glomeruli from patients with DKD and DKD sera-treated human podocytes, where it prevented αVβ₃ integrin activation by its interaction with suPAR and led to increased RhoA activity, rendering podocytes more susceptible to apoptosis. In vivo, inhibition of acid sphingomyelinase reduced proteinuria in experimental DKD but not FSGS, indicating that SMPDL3b expression levels determined the podocyte injury phenotype. These observations suggest that SMPDL3b may be an important modulator of podocyte function by shifting suPAR-mediated podocyte injury from a migratory phenotype to an apoptotic phenotype and that it represents a novel therapeutic glomerular disease target.     

Recent Progress in the Pathophysiology and Treatment of FSGS Recurrence

Focal segmental glomerulosclerosis (FSGS) is a glomerular disease characterized by proteinuria, frequent progression to end‐stage renal disease, and recurrence after kidney transplantation in ～25% of patients, which negatively impacts long‐term allograft survival. Experimental studies suggest that abnormalities in T and, possibly, B cells may represent one initial pathogenic trigger, leading to podocyte injury and progressive loss. New data also support the existence of circulating permeability factors able to damage the podocytes, but no single molecule has been consistently identified as the causal pathogenic element in FSGS recurrence. Unfortunately, major progress from mechanistic studies has not translated into substantial advancements in patient treatment, with plasmapheresis (PP) and high doses of cyclosporine (CsA) remaining the mainstays of therapy. Despite consistent experimental and clinical evidence that treatment of proteinuria slows renal function decline in proteinuric nephropathies, maximal use of antiproteinuric agents such as renin angiotensin system antagonists is not routine in the management of FSGS recurrence. More recently, encouraging results have been reported with anti‐CD20 depleting antibody rituximab, but further studies are needed to establish its safety/efficacy profile.     

口服爱若华联合甲基强的松龙肾囊注射治疗原发性局灶节段性肾小球硬化9例报告

目的探讨新型免疫抑制剂来氟米特(商品名:爱若华)和肾囊注射甲基强的松龙联合治疗局灶节段性肾小球硬化症(FSGS)的疗效和安全性。方法从我院2002年前经肾活检患者中确诊为FSGS的16例患者中随机选取10例(均采用常规类固醇口服治疗)患者作为对照组,从2002年始所有肾穿刺确诊为FSGS的9例患者作为治疗组,采用口服爱若华,同时肾囊注射甲基强的松龙长期治疗1年。在治疗前及治疗6个月、1年后观察24h尿蛋白定量、血尿素(Urea)、血肌酐(Scr)、内生肌酐清除率(Ccr)等指标变化,按照疗效评定标准对比分析联合治疗实验组与常规治疗对照组的疗效和安全性。结果联合治疗组显著降低24h尿蛋白定量,其中治疗6个月蛋白尿完全缓解率为34.5%、部分缓解率为44.5%,明显高于对照组(17.5%、25.4%)(P<0.01);12个月完全缓解率累加为67%(对照组:29.8%),部分缓解率累加为21.3%(对照组:38.5%)(P<0.01)。疗程中未发现糖皮质激素的副作用,有2例发现一过性来氟米特致肝酶升高,减量和对症治疗后恢复正常。结论爱若华联合肾囊注射甲基强的松龙治疗FSGS较常规治疗有效,副作用少,值得进一步研究与观察。